// 对象关联
Foo = { 
    init: function(who) { 
    this.me = who; 
    }, 
    identify: function() { 
    return "I am " + this.me; 
    } 
   }; 
   Bar = Object.create( Foo ); 
   Bar.speak = function() { 
    console.log( "Hello, " + this.identify() + "." ); 
   }; 
   var b1 = Object.create( Bar ); 
   b1.init( "b1" ); 
   var b2 = Object.create( Bar ); 
   b2.init( "b2" ); 
   b1.speak(); 
   b2.speak()
   console.log(b1.me.__proto__);